Not Applicable.
1. Field of the Invention
The present invention is directed generally to a capacitor and method for forming a capacitor and, more particularly, to a capacitor and method for forming a capacitor having an electrode formed from a transition metal, a conductive metal-oxide, alloys thereof, or combinations thereof.
2. Description of the Background
Minimum feature sizes in integrated circuits are sufficiently small that some fabrication processes are no longer effective. For example, in many applications sputter deposition is not effective for filling openings. Furthermore, the smaller dimensions are requiring higher performance from components and devices. For example, greater capacitance is required from small capacitors. One way to obtain higher capacitance is to use dielectrics having greater dielectric constants. Often, however, it is necessary to heat the dielectric to high temperatures in order to obtain the higher dielectric constant, and such heating can have adverse effects on the electrodes used to form the capacitor. For example, the electrodes will often oxidize, and the oxide will act as a lower permittivity dielectric in series with a higher permittivity dielectric. As a result, the oxide formed from the electrode will increase the effective distance between the electrodes, thereby decreasing the capacitance.
Therefore, the need exists for a capacitor and method for forming capacitors that do not suffer adverse effects when used with dielectrics having high dielectric constants.
The present invention is directed to a capacitor including a first electrode selected from a group consisting of transition metals, conductive metal-oxides, alloys thereof, and combinations thereof. The capacitor also includes a second electrode and a dielectric between the first and second electrodes. The present invention may be used to form capacitors in integrated circuits, such as those in memory devices and processors.
The present invention also includes a method of forming a capacitor. The method includes forming a first electrode selected from a group consisting of transition metals, conductive metal-oxides, alloys thereof, and combinations thereof. The method also includes forming a second electrode and forming a dielectric between the first and second electrodes.
The present invention solves problems experienced with the prior art because it provides for capacitors having improved physical structures, such as higher capacitance, smaller physical size, and smaller footprint, by utilizing improved dielectric properties, including electrodes that do not form dielectrics during subsequent processing steps. Those and other advantages and benefits of the present invention will become apparent from the description of the preferred embodiments hereinbelow.